Classification and Grade of Rapidly Quenched Alloys (GB/T15019-1994)
Rapidly quenched alloys, also known as ultra-high strength alloys, are obtainable by cooling the alloys quickly below the upper critical temperature. Rapidly quenched alloys have higher strength and other properties than commonly used alloys, such as steels and aluminum alloys. Therefore, rapidly quenched alloys are widely used in the manufacture of ultra-high strength components and parts, such as in aerospace and military industries.
Rapidly quenched alloys falling within the scope of this standard are classified and graded according to their chemical composition and mechanical properties. According to GB/T15019-1994, the classification and grade of rapidly quenched alloys are as follows.
Class A: Low-Carbon Low-Alloy Steels
Grade L1: Cr-V steel containing 0.1-0.2% C, 9.0-10.0% Cr and 0.1-0.4% V.
Grade L2: Ni-Cr-V steel containing 0.11-0.18% C, 9.0-10.0% Cr, 0.1-0.4% V, and 7.0-9.0% Ni.
Grade L3: Cr-V-Mo-Nb steel containing 0.11-0.20% C, 8.0-9.5% Cr, 0.1-0.5% V, 0.5-1.0% Mo and 0.2-0.5% Nb.
Grade L4: Ni-Cr-Mo-V steel containing 0.17-0.24% C, 8.5-9.5% Cr, 0.5-1.5% Mo, 0.1-0.5% V and 6.5-8.5% Ni.
Class B: Heat-Resistant Steels
Grade H1: Cr-Mo-V steel containing 0.11-0.16% C, 10.0-12.0% Cr, 0.4-0.7% Mo, 0.2-0.4% V and 0.2-1.0% Ti.
Grade H2: Ni-Cr-Mo-V steel containing 0.14-0.19% C, 10.0-12.0% Cr, 0.4-0.7% Mo, 0.2-0.4% V, 1.5-2.5% Ni and 0.2-1.0% Ti.
Class C: Aluminum Alloy
Grade AL1: Aluminum alloy containing 1.5-2.5% Si, 0.3-0.5% Mn and 0.2-0.5% Mg.
Grade AL2: Aluminum alloy containing 4.0-6.0% Si, 0.3-0.6% Mn and 0.3-0.8% Mg.
Grade AL3: Aluminum alloy containing 6.0-8.0% Si, 0.6-1.0% Mn and 0.5-1.0% Mg.
Class D: Copper-Base Alloy
Grade CU1: Copper alloy containing 0.3-0.6% Si, 0.3-0.8% Al, 0.1-0.3% Mn, 0.3-0.5% Ni and 0.2-0.5% Fe.
Grade CU2: Copper alloy containing 1.0-3.0% Si, 0.5-1.5% Al, 0.1-0.3% Mn, 0.3-0.5% Ni and 0.2-0.5% Fe.
Rapidly quenched alloys are classified according to the above classification and grade system. They are produced, inspected and identified according to the corresponding grade and standard.
